Medical systems include a medical device and attached medical leads. The medical device which is located in a location generally convenient for implantation generates stimulation signals that are then directed to a target site by the medical leads. The medical leads include contacts that receive the stimulation signals from the medical device and include conductors that extend to a distal end where electrodes are present. The electrodes then pass the stimulation signals to the body tissue at the target site.
Generally, a particular port of a medical device has a set number of electrical connectors. The proximal end of a given medical lead designed for the medical device has a number of contacts on the proximal end and electrodes on the distal end that match the number of electrical contacts of the medical device port. In some cases, it may be desirable to drive stimulation signals to two different leads using a single port of a medical device. In such a case, an adapter may be used that has a lead portion that is installed into the medical device port and has two or more ports, one port for each lead to be driven by the signal medical device port.
Typically, such an adapter may define a primary lead and a secondary lead. In one simple case, one or more secondary leads may be driven by all electrical connectors in an identical manner as the primary lead. In other more complex cases, the primary lead is driven by the most electrical contacts of the medical device while the one or more secondary leads are driven in an identical fashion by the fewest electrical connectors. One specific example is using a spinal cord stimulation paddle lead as the primary lead, where five or more electrodes are individually controlled to create a specific stimulation pattern from the paddle. In this example, a peripheral stimulation percutaneous lead may be used as the secondary lead where only two or three electrical contacts from the medical device drive the secondary lead. Adapters distribute the stimulation from the few electrical contacts of the medical device to the several electrodes of the secondary lead in a fixed, pre-determined configuration and thus produce a pre-determined stimulation pattern. As a consequence, clinicians have no way to customize the configuration and resulting stimulation pattern of the secondary lead connected to a given adapter.